[lcd4linux] expression help

[Matt <mj...@ii...>]

Hi all,

I'm trying to figure out how the evaluator/expressions and other 
components work together and I have become stuck.

I have a some sensor data in a mysql db.
I want to show the latest data  and indicate whether it rising or 
falling by comparing it to the average temp in in the last 5 mins.
Here's my widget for outside temperature.

Widget 1WeatherOutsideTemp {
    class 'Text'
# this is average over the last 5 minutes
    expression2 v2=MySQL::query('SELECT AVG(value) FROM sample WHERE 
id=11 AND timestamp>NOW()-INTERVAL 5 MINUTES')

# this is the last recorded sample
    expression v1=MySQL::query('SELECT value FROM lastsample WHERE id=11')

    width 4
    align 'R'
    precision  1
# if the last sample is bigger than the last 5min average show +
# if the last sample is smaller than the last 5min average show -
# else show nothing
    postfix v1>v2?'+':(v1<v2?'-':' ')
    prefix ''
    update minute
}


However, it doesn;t every use a minus sign or anything other than a plus.
This makes me think theres something fundamental about how I'm using the 
expressions.

Also, I'd like to replace the '+' and '-' with an icon, but I'm not sure 
of the syntax.

Could someone help?


Thanks

Matt